[vsnet-grb-info 6455] GRB 080804, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8067
SUBJECT: GRB 080804, Swift-BAT refined analysis
DATE:    08/08/05 15:54:46 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

C. Markwardt (GSFC/UMD), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), K. McLean (GSFC/UMD), D. Palmer (LANL),
J. L. Racusin (PSU), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080804 (trigger #319016)
(Racusin, et al., GCN Circ. 8057).  The BAT ground-calculated position is
RA, Dec = 328.675, -53.189 deg which is 
   RA(J2000)  =  21h 54m 41.9s 
   Dec(J2000) = -53d 11' 20.2" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 19%.
 
The mask-weighted light curve shows the main peak starting at ~T-10sec,
peaking at ~T+2 sec, and ending at ~T+100 sec.  T90 (15-350 keV) is
34 +- 16 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.4 to T+62.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.19 +- 0.09.  The fluence in the 15-150 keV band is 3.6 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.57 sec in the 15-150 keV band
is 3.1 +- 0.4 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/319016/BA/